Viral nucleolar localisation signals determine dynamic trafficking within the nucleolus

Virology. 2008 Oct 25;380(2):191-202. doi: 10.1016/j.virol.2008.05.032. Epub 2008 Sep 4.


Localisation of both viral and cellular proteins to the nucleolus is determined by a variety of factors including nucleolar localisation signals (NoLSs), but how these signals operate is not clearly understood. The nucleolar trafficking of wild type viral proteins and chimeric proteins, which contain altered NoLSs, were compared to investigate the role of NoLSs in dynamic nucleolar trafficking. Three viral proteins from diverse viruses were selected which localised to the nucleolus; the coronavirus infectious bronchitis virus nucleocapsid (N) protein, the herpesvirus saimiri ORF57 protein and the HIV-1 Rev protein. The chimeric proteins were N protein and ORF57 protein which had their own NoLS replaced with those from ORF57 and Rev proteins, respectively. By analysing the sub-cellular localisation and trafficking of these viral proteins and their chimeras within and between nucleoli using confocal microscopy and photo-bleaching we show that NoLSs are responsible for different nucleolar localisations and trafficking rates.

MeSH terms

  • Animals
  • Artificial Gene Fusion
  • Capsid Proteins / genetics
  • Capsid Proteins / metabolism
  • Cell Line
  • Cell Nucleolus / virology*
  • Genes, Reporter
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Microscopy, Confocal
  • Protein Sorting Signals*
  • Protein Transport
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism
  • Trans-Activators / genetics
  • Trans-Activators / metabolism
  • Viral Proteins / metabolism*
  • rev Gene Products, Human Immunodeficiency Virus / metabolism


  • Capsid Proteins
  • ORF57 protein, Herpesvirus saimiri
  • Protein Sorting Signals
  • Recombinant Fusion Proteins
  • Repressor Proteins
  • Trans-Activators
  • Viral Proteins
  • enhanced green fluorescent protein
  • rev Gene Products, Human Immunodeficiency Virus
  • rev protein, Human Immunodeficiency Virus-1
  • Green Fluorescent Proteins